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Temperature A to D readings now done using a moving average, like the Z probe.

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This commit is contained in:
Adrian Bowyer 2014-04-10 17:22:22 +01:00
parent 33cf94e0cf
commit 00d236c5ba
2 changed files with 36 additions and 19 deletions
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23
Platform.cpp
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@ -204,6 +204,7 @@ void Platform::Init()
if(heatOnPins[i] >= 0)
pinModeNonDue(heatOnPins[i], OUTPUT);
thermistorInfRs[i] = ( thermistorInfRs[i]*exp(-thermistorBetas[i]/(25.0 - ABS_ZERO)) );
tempSum[i] = 0;
}
if(coolingFanPin >= 0)
@ -212,6 +213,8 @@ void Platform::Init()
analogWrite(coolingFanPin, 0);
}
NumAtoDReadingsAveraged = 8; // must be an even number, preferably a power of 2 for performance, and no greater than 64
InitialiseInterrupts();
addToTime = 0.0;
@ -251,6 +254,7 @@ void Platform::Spin()
if(Time() - lastTime < 0.006)
return;
PollZHeight();
PollTemperatures();
lastTime = Time();
ClassReport("Platform", longWait);
@ -359,15 +363,18 @@ void Platform::ClassReport(char* className, float &lastTime)
float Platform::GetTemperature(int8_t heater)
{
// If the ADC reading is N then for an ideal ADC, the input voltage is at least N/(AD_RANGE + 1) and less than (N + 1)/(AD_RANGE + 1), times the analog reference.
// So we add 0.5 to to the reading to get a better estimate of the input. But first, recognise the special case of thermistor disconnected.
int rawTemp = GetRawTemperature(heater);
if (rawTemp == AD_RANGE)
{
// Thermistor is disconnected
return ABS_ZERO;
}
// So we add 0.5 to to the reading to get a better estimate of the input.
int rawTemp = tempSum[heater]/NumAtoDReadingsAveraged; //GetRawTemperature(heater);
// First, recognise the special case of thermistor disconnected.
// if (rawTemp == AD_RANGE)
// {
// // Thermistor is disconnected
// return ABS_ZERO;
// }
float r = (float)rawTemp + 0.5;
return ABS_ZERO + thermistorBetas[heater]/log( (r*thermistorSeriesRs[heater]/((AD_RANGE + 1) - r))/thermistorInfRs[heater] );
r = ABS_ZERO + thermistorBetas[heater]/log( (r*thermistorSeriesRs[heater]/((AD_RANGE + 1) - r))/thermistorInfRs[heater] );
return r;
}

32
Platform.h
View file

@ -189,7 +189,6 @@ const unsigned int httpOutputBufferSize = 2 * 1432;
#define BAUD_RATE 115200 // Communication speed of the USB if needed.
const uint16_t lineBufsize = 256; // use a power of 2 for good performance
const uint16_t NumZProbeReadingsAveraged = 8; // must be an even number, preferably a power of 2 for performance, and no greater than 64
/****************************************************************************************************/
@ -549,6 +548,7 @@ class Platform
int zProbeADValue;
float zProbeStopHeight;
bool zProbeEnable;
// AXES
void InitZProbe();
@ -557,14 +557,13 @@ class Platform
float axisLengths[AXES];
float homeFeedrates[AXES];
float headOffsets[AXES]; // FIXME - needs a 2D array
// bool zProbeStarting;
// float zProbeHigh;
// float zProbeLow;
// HEATERS - Bed is assumed to be the first
int GetRawTemperature(byte heater) const;
void PollTemperatures();
long tempSum[HEATERS];
int8_t tempSensePins[HEATERS];
int8_t heatOnPins[HEATERS];
float thermistorBetas[HEATERS];
@ -582,7 +581,8 @@ class Platform
float standbyTemperatures[HEATERS];
float activeTemperatures[HEATERS];
int8_t coolingFanPin;
//int8_t turnHeatOn;
uint16_t NumAtoDReadingsAveraged; // Smoothing filter on A to D readings
// Serial/USB
@ -815,10 +815,12 @@ inline void Platform::PollZHeight()
{
uint16_t currentReading = GetRawZHeight();
// We do a moving average of the probe's A to D readings to smooth out noise
if (zModOnThisTime)
zProbeOnSum = zProbeOnSum + currentReading - zProbeOnSum/NumZProbeReadingsAveraged;
zProbeOnSum = zProbeOnSum + currentReading - zProbeOnSum/NumAtoDReadingsAveraged;
else
zProbeOffSum = zProbeOffSum + currentReading - zProbeOffSum/NumZProbeReadingsAveraged;
zProbeOffSum = zProbeOffSum + currentReading - zProbeOffSum/NumAtoDReadingsAveraged;
zModOnThisTime = !zModOnThisTime;
@ -832,18 +834,18 @@ inline void Platform::PollZHeight()
inline int Platform::ZProbe() const
{
return (zProbeType == 1)
? (zProbeOnSum + zProbeOffSum)/NumZProbeReadingsAveraged // non-modulated mode
? (zProbeOnSum + zProbeOffSum)/NumAtoDReadingsAveraged // non-modulated mode
: (zProbeType == 2)
? (zProbeOnSum - zProbeOffSum)/(NumZProbeReadingsAveraged/2) // modulated mode
? (zProbeOnSum - zProbeOffSum)/(NumAtoDReadingsAveraged/2) // modulated mode
: 0; // z-probe disabled
}
inline int Platform::ZProbeOnVal() const
{
return (zProbeType == 1)
? (zProbeOnSum + zProbeOffSum)/NumZProbeReadingsAveraged
? (zProbeOnSum + zProbeOffSum)/NumAtoDReadingsAveraged
: (zProbeType == 2)
? zProbeOnSum/(NumZProbeReadingsAveraged/2)
? zProbeOnSum/(NumAtoDReadingsAveraged/2)
: 0;
}
@ -887,6 +889,14 @@ inline int Platform::GetRawTemperature(byte heater) const
return 0;
}
inline void Platform::PollTemperatures()
{
// We do a moving average of each thermometer's A to D readings to smooth out noise
for(int8_t heater = 0; heater < HEATERS; heater++)
tempSum[heater] = tempSum[heater] + GetRawTemperature(heater) - tempSum[heater]/NumAtoDReadingsAveraged;
}
inline float Platform::HeatSampleTime() const
{
return heatSampleTime;